1. Field of the Invention
The present invention relates to a seesaw switch provided in a vehicle panel.
2. Description of Related Art
Seesaw switches are provided in vehicle panels such as instrument panels so as to provide various controls of audio and air conditioning devices. A conventional structure of such a seesaw panel is shown in schematic diagrams of FIGS. 9(a) and (b). A seesaw switch 500 includes, as shown in FIGS. 9(a) and (b), a pair of switch elements 512a, 512b provided on a substrate 510; an operating member 560 that presses and operates the switch elements 512a, 512b; and pressure transmitting members 540a, 540b provided between the operating member 560 and the switch elements 512a, 512b, respectively. The operating member 560 has pressing sections 560a, 560b provided at corresponding locations to the switch elements 512a, 512b, respectively. A rotating axis 560c is located between the pressing sections 560a, 560b and supports rotational displacement of the pressing sections pivoting around the rotating axis 560c. The pressure transmitting members 540a, 540b press the switch elements 512a, 512b, respectively, by displacement of the pressing sections 560a, 560b in a pressing direction as the operating member 560 rotates.
In the seesaw switch 500, the operating member 560 is pressed and operated. When the operating member 560 is rotationally displaced from a neutral position shown in FIG. 9(a) to another position shown in FIG. 9(b), the first pressing section 560b of the operating member 560 is displaced in a pressing direction along with the rotational displacement. Then, the pressure transmitting member 540b presses the switch element 512b. When the operation member 560 is rotationally displaced in the opposite direction from this pressing state, the operation member 560 moves back to the position shown in FIG. 9(a) and releases the pressing state of the switch element 512b. 
With the above-mentioned seesaw switch 500, when the operation member 560 is rotatably displaced from the neutral position as shown in FIG. 9(b), the second pressing section 560a of the operation member 560 and the pressure transmitting member 540a are separated. Consequently, when the operation member 560 moves back to the neutral position, the pressing section 560a of the operation member 560 and the pressure transmitting member 540a collide with each other and generate a collision noise, which brings discomfort to the user and the like.
In order to address the problem, Related Art 1 discloses a seesaw switch that provides springs on the pressure transmitting members 540a, 540b, the springs constantly contacting on a rear surface the operation member 560 while being deformed elastically, and biasing, through their elasticity, the operation member in a direction opposite to the pressing direction.
With this seesaw switch, even when the operation member 560 is rotated from the neutral position and the first pressing section 560b of the operation member 560 is displaced in the pressing direction, the spring for the pressure transmitting member 540a is in contact with the rear surface of the second pressing section 560a. Therefore, even when the operation member 560 is moved back from this state to the neutral position, it is possible to suppress a sudden collision between the second pressing section 560a and the pressure transmitting member 540a, thereby suppressing the uncomfortable collision noise.
The above-described seesaw switch, however, requires a complex structure because of the springs installed to the respective pressure transmitting members 540. Further, the seesaw switch needs to be assembled while the springs are elastically deformed, which complicates the assembly.
In addition, with the above-described seesaw switch, the operation member 560 needs to be pressed while elastically deforming the springs against the biasing force of the springs. Therefore, an operation power greater than force to operate a non-seesaw switch including no spring is required, the non-seesaw switch being a push switch, for example, that does not need to include any spring due to absence of the collision noise. Then, the user may feel it is unnatural that variations of power are required for operating switches when the above-described seesaw switches and push switches and the like are located on one instrument panel, for example. Moreover, when springs are provided to the push switch and the like in order to equalize the operation power, even though they are not needed for the switch, the overall cost for the entire apparatus may become expensive.    [Related Art 1] Japanese Patent Laid-Open Publication 2006-40562